In recent years, the fishery products have been improved as superior protein foods and in particular they have been evaluated as superior food materials in view of health of a person. As the processed foods of the fishery product, a fish-paste product such as boiled fish paste has been widely known and frozen ground fish has been frequently used as its raw material.
However, due to the fact that there were many kinds of fishery products, flesh tastes were substantially different from each other in view of age, sex, seasons and nutritive conditions or the like and in particular, the muscles of the fishery products contained 70 to 80% moisture therein, deteriorations in quality such as reduction in weight, flesh collapse, hardening or oxidation of flesh tissue or the like caused by discharging of drips of the fishery product in the case that the fishery products were processed (frozen, refrigerated, stored with salt and heating or the like) have become a problem.
In view of this fact, as means for improving these prior art problems, various kinds of processing methods have been proposed.
1. In the gazette of Japanese Patent Laid-Open No. Sho 53-50358 is disclosed a processed food manufacturing method in which salt is added to fine flesh and plant albumin to form paste and then oil and fat and heat solidifying raw material are non-uniformly mixed from each other and they are gradually frozen.
2. In the gazette of Japanese Patent Laid-Open No. Sho 54-2368 is disclosed a smoked and processed fish flesh product in which a step for getting a bonito pickled in sorbitol liquid of NaHCO.sub.3 and NaHPO.sub.4 and a step for sprinkling with salt are concurrently carried out or almost simultaneously to soften the flesh quality or stabilize flesh pigment tissue.
3. In the gazette of Japanese Patent Laid-Open No. Sho 55-144844 is disclosed a fishery frozen food manufacturing method in which a fish flesh with bones is pickled in solution of salt, sodium bicarbonate, alkaline phosphate, dehydrated and the flesh is pressurized, heated and then frozen.
4. In the gazette of Japanese Patent Laid-Open No. Sho 57-5668 is disclosed a fish flesh ham manufacturing method in which a fish flesh is pickled in solution of sodium hydrogencarbonate of 0.3 to 1.0% and sorbitol of 0.3 to 1.0% or their mixed solution, dehydrated, and after this dehydration, the flesh is pickled in salt solution, and processed with casing to improve a fish flesh binding state.
5. In the gazette of Japanese Patent Laid-Open No. Sho 62-19069 is disclosed an edible protein raw material manufacturing method in which soft tissue of a walleye pollack bleached with water is pickled in mixture liquid of edible oil or salt or saccharide for a longer hour so as to improve its state, and gradually frozen.
6. In the gazette of Japanese Patent Laid-Open No. Hei 6-165634 is disclosed a processed marine product pre-processing method in which inorganic salt is dissolved in aqueous solution of sodium chloride acting as pre-processing agent, sodium carbonate is added to keep a value of pH of entire aqueous solution in alkaline state, the marine product is pickled in the pre-processing liquid for a longer hour and kept at 0 to 20.degree. C., boiled and thawed in order to keep deterioration in quality caused by processing of the marine product at a minimum value.
7. In the gazette of Japanese Patent Laid-Open No. Sho 62-49012 is disclosed a shark flesh frozen cut tissue manufacturing method in which the shark cut tissue is added directly with saccharide, polymerization phosphate (6 to 12 weight parts, polymerization phosphate of 0.05 to 0.4 weight parts and dimetallic salt (0.2 to 1.0 weight parts) without bleaching with water, then sufficiently agitated by an agitating machine, frozen at -40.degree. C. and occurrence of bad odor during processing is prevented.
8. In the gazette of Japanese Patent Laid-Open No. Sho 53-145948 is disclosed a manufacturing method in which a whale flesh is cut into a desired thickness, washed with water, salt of 1 to 3% is added to the flesh, salt soluble protein only at the surface of the flesh is dissolved by an agitating and mixing machine without damaging its inner tissue, the flesh is molded under a reduced pressure of 70 mmHg, then heated in hot water of 90.degree. C. for 2 hours and 30 minutes, the flesh is cut into a proper shape and canned with whale blocks.
9. In the gazette of Japanese Patent Laid-Open No. Hei 4-311374 is disclosed a method in which fish with deteriorated freshness and fish with soft flesh tissue are added with quality improving agent of calcium chloride or salt after its bleaching with water or its preliminary dehydration so as to make a resilient fish flesh.
10. In the gazette of Japanese Patent Laid-Open No. Sho 62-130667 is disclosed a frozen ground flesh in which sodium carbonate (0.04 to 0.06%) and/or sodium hydrogencarbonate 0.05 to 0.15% is added during pickling at the ground flesh manufacturing stage and its value of pH is adjusted to 7.5 or less.
11. In the gazette of Japanese Patent Laid-Open No. Hei 2-295466 is disclosed a resilient paste product manufacturing method in which basic calcium of 0.01 to 0.1 weight parts is added to get a value of pH of 7.3 to 8.5 and animal and plant proteins of 0.5 to 5 weight parts is added during manufacturing of fish paste product.
12. In the gazette of Japanese Patent Laid-Open No. Hei 2-203769 is disclosed a fish paste product manufacturing method in which calcium salt, magnesium salt and strontium salt are applied during bleaching with water to prevent a flowing-out of a protein cross-linking factor and adding of phosphate enables its to be increased.
13. In the gazette of Japanese Patent Laid-Open No. Hei 1-222761 is disclosed a method in which a fish flesh is finely divided into powder by a homoginizer in phosphate (0.2% or less) or sodium bicarbonate solution at the stage of bleaching with water, the flesh is bleached with water for 20 minutes under a reduced pressure by 100 mmHg so as to improve a gelation forming capability.
14. In the gazette of Japanese Patent Laid-Open No. Sho 54-80456 is disclosed a corn beef manufacturing method in which a raw material meat of block form is scarred, thereafter phosphate compounding agent and adding agent such as salt are added, the meat is agitated and mixed under a reduced pressure of 60 cmHg or more to perform a pickling operation, and a manufacturing yield is improved by 15 to 20%.
15. In the gazette of Japanese Patent Laid-Open No. Sho 59-39111 is disclosed a chicken block manufacturing method in which salt of 1 to 3% is added to a chicken, a gradual agitation and mixing is applied to the chicken, salt soluble protein of meat-paste like form is dissolved out at the surface of the meat block, the meat is fed into a mold under a reduced pressure and filled in it, the meat is further heated and solidified.
16. In the gazette of Japanese Patent Laid-Open No. Sho 62-29953 is disclosed a meat processed product manufacturing method in which pickle liquid heated with water vapour is injected into meat to get meat processed product having a low salt amount, low calorie and low phosphoric acid.
17. In the gazette of Japanese Patent Laid-Open No. Hei 3-180138 is disclosed a seasoned meat manufacturing method in which proper amounts of saccharide, binding agent, coloring auxiliary agent, emulsion stabilizer agent, pH adjusting agent or the like as well as a major substance of ground salt and a raw material meat is immersed for 10 to 30 hours in a large amount of pickle solution having a composition of which concentration is approximately equal to that of body liquid.
18. In the gazette of Japanese Patent Laid-Open No. Sho 58-37826 is disclosed a sheet-of-meat block manufacturing method in which sodium salt is added to a meat block, ion intensity at the surface of the meat block is adjusted to 0.6 or more, actomyosin is dissolved at the surface of the meat block, frozen at -2 to -8.degree. C., thereafter molded under a pressure of 3 to 70 kg/cm.sup.2 and the meat blocks are contacted from each other.
19. In the gazette of Japanese Patent Laid-Open No. Hei 2-308774 is disclosed a method of reforming small pieces of meat in which paste meat having the myofibril protein dissolution agent such as salt added to small pieces of meat with 10 to 90 weight parts to have a pH value of 6.0 to 7.3 and mixture meat having residual small pieces of meat with 90 to 10 weight parts to have a pH value of 6.5 or less are kneaded to each other under application of a vacuum agitator, a line mill and a liner mixer while avoiding mixing of oxygen gas.
However, each of the aforesaid prior art processing methods had the following problems.
(1) The method disclosed in Japanese Patent Laid-Open No. Sho 53-50358 is operated such that plant protein and salt are added to fine meat, crushed to each other to make paste-like meat, fat is blended with the paste and thereafter a gradual freezing is carried out for 5 hours to several days to make an alternative product for roast ham and the like. However, this method had a problem that a product temperature was increased due to friction during crushing operation, its quality could easily be deteriorated, and a cooling operation or the like was required to prevent the product temperature from being increased and its poor working characteristic was resulted. In addition, this method had a problem that a bonding feature of fish flesh was reduced due to an easy discharging of drip under activation of enzyme, the bonding characteristic of the fish flesh was reduced due to adsorption of drip with flesh paste, plant protein was required to accommodate for it to deteriorate taste of the flesh. Accordingly, this method had a problem that the fish flesh could not be made of full fish, manufacturing also required longer hours, various problems were found in view of quality as well as sanitation and further it had a low productivity.
(2) The method disclosed in Japanese Patent Laid-Open No. Sho 54-2368 had a problem that blood of fish flesh such as a bonito which was easily hardened and changed in color to charcoal after cooking was removed with salt water, salt was sprinkled over it for pickling it for 48 hours, then the flesh was pickled in bicarbonate soda, secondary phosphate soda and sorbitol liquid to soften the tissue quality, although a large amount of salt were sprinkled over the surface of the tissue, resulting in that the tissue was bitter, a salt pickling stage required longer hours, fine elements of low molecular weight such as water soluble protein was dissolved and discharged out, its yield was reduced, a poor productivity occurred and a concentration of salt was high. In addition, it had a problem that its taste was deteriorated and a pickling stage required longer hours, resulting in that its productivity was poor.
(3) Although the method disclosed in Japanese Patent Laid-Open No. Sho 55-144844 enabled fish flesh to be eaten together with bones and showed a superior taking of calcium, it had a problem that its working during manufacturing was troublesome, showed a poor workability and had a poor productivity. In addition, this method had a problem that it had pressurizing and heating stages, nutritious substances were damaged and nutrition of fish could not be fully utilized.
(4) Although the method disclosed in Japanese Patent Laid-Open No. Sho 57-5668 was preferable for improving binding feature of fish flesh ham, it had a problem that quality of fish flesh might easily be deteriorated due to a long pickling time. In addition, it had a problem that a temperature controlling operation was troublesome due to restriction on deterioration of quality and it had a poor productivity. In addition, it had a problem that water soluble protein as well as taste substance of low molecule or effective nutritious substance and the like were dissolved and discharged out.
(5) Although the method disclosed in Japanese Patent Laid-Open No. Sho 62-19069 was preferable to improve fish flesh such as a walleye pollack having soft tissue or dry and crumbling taste, it had a problem that effective nutritious substances such as fat or low molecular protein substance were discharged into mixture liquid of edible oil or salt or saccharide by an osmotic pressure, the fish flesh was lack in nutritious value and lack in binding feature, and also its processing characteristic was lack.
(6) Although the method disclosed in Japanese Patent Laid-Open No. Hei 6-165634 had an effect to restrict deterioration in quality associated with a processing of marine products, it had a problem that its pickling operation required a longer time and was lack in productivity. In addition, it had a problem that drip of taste substances or the like was dissolved into the processing liquid during a pickling of longer time by osmotic pressure or deterioration in quality was generated during pickling operation.
(7) Although the method disclosed in Japanese Patent Laid-Open No. Sho 62-49012 was preferable for processing sharks containing urea, trimetyleamioxide of about 10 to 20 times of that of normal fish and producing bad odor of ammonia and trimetylamine as a degree of freshness of sharks was decreased, it had a problem that quality might easily be deteriorated during rubbing with salt due to requiring of a step of rubbing with salt and inclusion of solid salt, and further its work was troublesome and lacked in productivity.
(8) The method disclosed in Japanese Patent Laid-Open No. Sho 53-145948 had a problem that after the flesh was bleached with water and its blood was removed, salt was added to the flesh and they were agitated, molded under a reduced pressure, it showed a low productivity due to complex production step, its taste substance was flowed out and then the flesh was lack in its nutritious value and the like.
(9) Although the methods disclosed in Japanese Patent Laid-Open Nos. Hei 4-311374, Sho 62-130667 and Hei 2-203769 were preferable for improving quality of fish having soft flesh tissue, they had a problem that when denatured portions of the myofibril protein were removed by adding salt during bleaching with water or strengthening of tissue was improved by increasing the number of times of bleaching with water or processing time, nutritious substance of low molecule was discharged out under the bleaching with water to cause its taste to be lack and also a product yield was decreased.
(10) Although the method disclosed in Japanese Patent Laid-Open No. Hei 2-295446 showed superior resiliency, texture or odor and the like, it had a problem in view of reaction time and resiliency when basic calcium, in particular, burned calcium was added, and its preservation under a high pH value.
(11) The method disclosed in Japanese Patent Laid-Open No. Hei 1-222761 is carried out such that a cut tissue is divided into fine pieces by a homogenizer in bleaching water (added with phosphate or tripoti acid chloride of 0.2% or sodium bicarbonate) and a pressure reduced bleaching at 100 mmHg is performed. Although fat were removed upon completion of the pressure reduced bleaching operation, this method had a problem of reduction in yield or reduction in productivity caused by complex production steps due to discharging of low molecular nutritious substance caused by bleaching with water, fine piece formation within the bleaching water or reduced pressure bleaching.
(12) The method disclosed in Japanese Patent Laid-Open No. Sho 54-80456 is carried out such that after the muscle membrane or the tendon of flesh pieces is cut into short pieces, additive agent is added to the pieces, the pieces are agitated under a reduced pressure condition, then they are pickled for 48 hours at 3 to 5.degree. C., boiled with vapour for 60 to 90 minutes at 115 to 118.degree. C., the processed flesh is untangled, the muscle membrane, tendon and blood vessel are removed to produce a product. Thus, this method had a problem of lack in productivity due to a complex working steps and longer working hours. In addition, it had a problem that the flesh showed a bad color as a corn beef and it was not preferable in view of safety and sanitation due to adding of phosphate, sodium nitrite and the like.
(13) The method disclosed in Japanese Patent Laid-Open No. Sho 59-39111 had a problem that the reaction was performed only at the surface of the flesh and quality of inner part in the flesh could not be improved. In addition, it had a problem that the processing step became a complex processing step due to requiring a molding operation of 12 to 48 hours under the pressure reduced state and a heating operation of 2 to 3 hours, its cost was highly expensive and it was lack in mass productivity.
(14) It was found that the method disclosed in Japanese Patent Laid-Open No. Sho 62-29953 or Hei 3-180138 showed that an effect of salt solution was poor due to a low concentration of salt and a flesh tissue quality improvement could not be carried out due to a quite slow gelation and emulsification. In addition, this method had a problem that the product was lack in texture such as resiliency or resistance to the teeth and further it had a problem that the flesh was easily oxidized and its color was easily faded. In addition, it had another problem that its quality was dispersed and a flesh block had bad color. Further, it had a problem that it was difficult to improve a layer of fat, flesh having a large amount of fat was easily dispersed in quality and had a poor productivity.
(15) The method disclosed in Japanese Patent Laid-Open No. Sho 58-37826 or Hei 2-308774 had a problem that it had a poor binding characteristic and the flesh was easily collapsed during heating operation due to the fact that elution reaction or bio-chemical reaction of actomyosin was not generated under the presence of the layer of fat in the flesh block. Due to this fact, there was a problem that a full utilization of waste flesh having a large amount of layers of fat was difficult and its workability was lack.
In addition, all these prior arts were processing methods in which the granular additives were sprinkled or the flesh was fully dipped in a large volume of processing and treating solution of low concentration, so that these methods had a problem that it required a longer hour working time to attain the intended object through these processing methods, reduction in quality of fish flesh (softening or hardening, oxidation) was produced and the yield was remarkably reduced. Due to this fact, these prior art methods had a problem that the texture or taste such as resistance to the teeth when the fish flesh was eaten was reduced. In addition, they had a problem that they required a wasting facility for processing a large amount of pickling liquid used for the pickling operation or fat or low molecular nutritious substances discharged out of fish flesh. Further, the prior art processing methods had a problem that they had no universal processing of fish flesh, but they could be utilized only in the specified application.